Evolution

Selected Domestically

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Science  02 Apr 2010:
Vol. 328, Issue 5974, pp. 18
DOI: 10.1126/science.328.5974.18-a
CREDIT: PHOTOS.COM

The role of duplicate genes in evolution remains contentious—whereas some have argued that they provide the raw material for evolutionary novelties on which selection acts, others have suggested that only less essential genes are maintained after they are duplicated. In flowering plants, the FLOWERING LOCUS T (FT) gene is an important determinant of fitness through its control of the time of flowering. Blackman et al. identified four FT genes in the sunflower that appear to have arisen via genus-specific duplications. Although the coding regions of all of these genes were conserved, their expression patterns differed; one of these replicates is not expressed and thus is probably nonfunctional. Transgenic Arabidopsis ft mutants expressing the wild sunflower genes showed accelerated flowering. However, an allele found in all domesticated sunflowers extended the time to flowering, suggesting that it may be a negative regulator. This allele shows signatures of selection consistent with domestication and provides an example of how the duplication of genes controlling development can bring about phenotypic change during domestication, and maybe during evolution generally.

Curr. Biol. 20, 10.1016/j.cub.2010.01.059 (2010).

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